186d with 3t72ha Runaway

thepumpguysc · Dec 2, 2021

The plungers are mated to its barrel and r not to be swapped.!!
Unless u mean injectors..??

thepumpguysc · Dec 2, 2021

Another thing to check is the glow plug in the intake..
If it’s leaking fuel into the intake, it’ll black smoke something terrible..

Jtthebrick · Dec 2, 2021

Ok, now I'm officially confused. I swapped plungers between 2-3 and reinstalled. Cranking with the lines off the pump produces a nice even pattern between all 3 cylinders. Fired it up and all three cylinders over fuel producing tons of black smoke and uncontrollable high rev. My thought is this pump was rebuild with the wrong plungers. any chance someone has a photo of part# H124950-51100 to compare?

Jtthebrick · Dec 2, 2021

thepumpguysc said:
Another thing to check is the glow plug in the intake..
If it’s leaking fuel into the intake, it’ll black smoke something terrible..

I was just looking at this. I had the fuel line unplugged from it and it would not start. How does this system work?

Jtthebrick · Dec 2, 2021

Just eliminated the glow plug from the equation. No change. Also I just noticed in the injection pump diagram which shows 2 spacers below the pump. Mine has a very thing copper gasket only. Looks like they are available from hoye.

thepumpguysc · Dec 3, 2021

Those copper looking parts are TIMING SHIMS.. do not mess w them..
Another thing that’s overlooked is, if u use some type of sealant under the pump.. it must b used sparingly.!!! It will change the timing of gobbed on..

Jtthebrick · Dec 3, 2021

I'm still working on the plunger theory. From what I can see online, mine differ from the correct part number.

thepumpguysc · Dec 3, 2021

Have u thought about the theory that someone turned the fuel up.??
Your not gonna fix anything until u can get from running away..
And u can’t do that until u get the injectors checked and get the pump gone thru by someone who KNOWS WHAT THEY’RE DOING..

careyo63 · Dec 4, 2021

Pump for a 187? Check those #'s. If I ever have to get into my pump it's getting sent out. I'll call it a YM240 and let JD. go through it. Not going to fool school for a Hyd . pump.

bmaverick · Dec 4, 2021

careyo63 said:
Pump for a 187? Check those #'s. If I ever have to get into my pump it's getting sent out. I'll call it a YM240 and let JD. go through it. Not going to fool school for a Hyd . pump.

Nope, you are off by one model number.

YM186D is the OPs request.

And it's the FUEL PUMP.